Disk films are furnished in the form of a film unit loaded in a cartridge, which are set in a camera exclusively used therefor, and, after photographs are taken, they are collected through agents to a centralized photographic processing facility, called a photofinishing laboratory, where photographic processing such as developing or printing is carried out.
In the photofinishing laboratory, the disk films are taken out from the cartridge by use of a cartridge opener, and a large number of films are set in a large-scale automatic processor at one time, which are processed while being rotated at a high velocity.
With regard to the photographic processing of disk films, disclosures are seen in U.S. Pats. No. 4,112,453, No. 4,132,469 and No. 4,188,106; in regard to the cartridge opener, Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 110829/1978, and U.S. Pats. No. 4,208,116 and No. 4,248,564; and in regard to their general matters, The Full View of Kodak disk film System [SHASHIN KOGYO (Photographic Industries), April Issue, 1982, pp.26-41].
The above are concerned with large-scale automatic processors, but automatic processors for use in the processing of disk films in numbers of one to ten sheets include those disclosed in Japanese Patent O.P.I. Publications No. 159146/1987, No. 178967/1987, No. 79018/1986, No. 143552/1988 and No. 273858/1988, filed by the present applicant.
In the case of the large-scale automatic processors or relatively small-sized automatic processors called minilabs (miniature photofinishing laboratories), processing solutions are stored in processing tanks or baths, and heated to a given temperature by means of a heater provided therein. In the processing baths, liquid level sensors are provided so that replenishing solutions previously heated may be supplied when processing has been carried out in a given quantity, lowering the liquid levels.
For example, in the case of small-sized automatic processors in which processing solutions are used in an amount of from several m1 to 1 l, the amount of processing solutions are reduced by evaporation and the deterioration of processing solutions is promoted by oxidation or the like when the processors left to stand for a long time, resulting in loss of stable processing performance when processing is resumed, irrespective of whether the processors are of the type in which processing solutions previously heated are supplied into processing baths, the type in which processing solutions are heated after they have been supplied into processing baths, or the type in which both of these types are used in combination.
This may remarkably occur when the capacity of processing baths is set to as small as about 1 ml to about 100 ml so that rapid processing can be carried out at high temperatures of, for example, about 40.degree. C. or more, and it is very difficult to have a processor ready for use with stable processing solutions.
In instances in which processing solutions are put into inconstant intermittent use without any preset use or non-use of the processor, it is also very difficult to maintain the processing solutions in a stable state.